This invention relates to fluid mixers, and more particularly to inline motionless mixers.
A myriad of processes require constituents to be mixed together to achieve a resultant uniform, homogeneous dispersion. Many prior art in-line mixers utilize shear and turbulence to effectuate such mixing. As a result, constituents may deteriorate and the degree of mixing achieved will vary widely.
In response to the need for an improved in-line mixer, the "motionless" mixer was developed. The motionless mixer is a fixed, in-line mixer comprising a plurality of mixing elements contained within a tubular housing. These mixing elements achieve the desired mixing by flow inversion (particle flow to and from the center of the mixer and from and to the wall of the housing), flow division (splitting and recombination of flow streams through the mixer), flow reversal, and/or flow rotation. Various mixing elements have been utilized including, inter alia, right and left-handed helices and tetrahedral chambers in fluid communication with each other. These elements are inserted within a tubular housing and held stationary therein by means of welds or retaining rings. In the latter instance, the retaining rings may be removed thereby facilitating axial withdrawal of the mixing elements from the tubular housing for cleaning.
One problem in utilizing a motionless mixer to blend a fluid in chemical equilibria is the resultant deposition of solid deposits and scale which can occur upon distrubing such equilibria by mixing. Scale tends to accumulate at the contact points between the mixing elements and the inner surface of the motionless mixer housing thereby bonding the mixing elements to the inner surface. This bond may be sufficient to prevent axial removal of the mixing elements from the mixer housing for cleaning. The complex geometrical configuration of the mixing elements limits insertion of a cleaning device into the housing to only a few inches, thus making the device difficult to clean.
Accordingly, it is an object of the present invention to provide a motionless mixer, the construction of which facilitates cleaning and reuse of the mixing elements.
Another object of the present invention is to provide a housing for an inline motionless mixer which is economical to construct and which is designed to be discarded after removal of the mixing elements therefrom.
These and other objects and advantages of the invention will be apparent from the following detailed description and drawing.